USPTO Patents Application 10716129

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WHAT IS CLAIMED IS :

1. A method for providing a current to a load,
comprising:

selecting a current provided to the load from
one of a fixed current, a constant power current, and a
variable current, the variable current being based on the
voltage across the load, the selecting requiring selecting
one of the fixed current, the variable current, and the
constant power current based on a predetermined priority,
the predetermined priority requiring selection of the
current that provides the lower magnitude current or
limits power dissipation of a current source providing
current to the load.

2. The method of claim 1, wherein selection of
the constant power current causes the current source to
emit a predetermined temperature.

3. The method of claim 1, wherein the
predetermined priority selects the constant power source

if the power dissipation of the current source exceeds a
predetermined level of power dissipation.

4. A circuit for providing current to a load,
the circuit comprising:

a first current loop that is adapted to provide
a fixed current;

a second current loop that is adapted to provide
a variable current;

a third current loop that is adapted to provide
a constant power current; and

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a priority circuit that receives a first signal
from the first current loop which indicates the level of
an available fixed current, a second signal from the
second current loop which indicates the level of an
available variable current, and a constant power signal
from a constant power loop which indicates the level of
power dissipation of a current source and selects one of
the first current loop, the second current loop, and the
constant power loop to provide current to the load based
on a predetermined priority signal, the predetermined
priority requiring selection of the current that provides
the lower magnitude current or limits power dissipation of
the current source.

5, The circuit of claim 4, wherein selection of
the constant power current causes the current source to
emit a predetermined temperature .

6. The method of claim 4, wherein the
predetermined priority selects the constant power source
if the power dissipation of the current source exceeds a
predetermined level of power dissipation.